config KERNEL_BUILD_USER
string "Custom Kernel Build User Name"
+ default "builder" if BUILDBOT
default ""
help
Sets the Kernel build user string, which for example will be returned
config KERNEL_BUILD_DOMAIN
string "Custom Kernel Build Domain Name"
+ default "buildhost" if BUILDBOT
default ""
help
Sets the Kernel build domain string, which for example will be
write to these files. Many common debugging facilities, such as
ftrace, require the existence of debugfs.
+# remove KERNEL_MIPS_FPU_EMULATOR after kernel 4.14 and 4.14 are gone
config KERNEL_MIPS_FPU_EMULATOR
bool "Compile the kernel with MIPS FPU Emulator"
default y if TARGET_pistachio
depends on (mips || mipsel || mips64 || mips64el)
+config KERNEL_MIPS_FP_SUPPORT
+ bool
+ default y if KERNEL_MIPS_FPU_EMULATOR
+
config KERNEL_ARM_PMU
bool
default n
depends on (arm || aarch64)
+config KERNEL_X86_VSYSCALL_EMULATION
+ bool "Enable vsyscall emulation"
+ default n
+ depends on x86_64
+ help
+ This enables emulation of the legacy vsyscall page. Disabling
+ it is roughly equivalent to booting with vsyscall=none, except
+ that it will also disable the helpful warning if a program
+ tries to use a vsyscall. With this option set to N, offending
+ programs will just segfault, citing addresses of the form
+ 0xffffffffff600?00.
+
+ This option is required by many programs built before 2013, and
+ care should be used even with newer programs if set to N.
+
+ Disabling this option saves about 7K of kernel size and
+ possibly 4K of additional runtime pagetable memory.
+
config KERNEL_PERF_EVENTS
bool "Compile the kernel with performance events and counters"
default n
Enable the extended profiling support mechanisms used by profilers such
as OProfile.
+config KERNEL_UBSAN
+ bool "Compile the kernel with undefined behaviour sanity checker"
+ help
+ This option enables undefined behaviour sanity checker
+ Compile-time instrumentation is used to detect various undefined
+ behaviours in runtime. Various types of checks may be enabled
+ via boot parameter ubsan_handle
+ (see: Documentation/dev-tools/ubsan.rst).
+
+config KERNEL_UBSAN_SANITIZE_ALL
+ bool "Enable instrumentation for the entire kernel"
+ depends on KERNEL_UBSAN
+ default y
+ help
+ This option activates instrumentation for the entire kernel.
+ If you don't enable this option, you have to explicitly specify
+ UBSAN_SANITIZE := y for the files/directories you want to check for UB.
+ Enabling this option will get kernel image size increased
+ significantly.
+
+config KERNEL_UBSAN_ALIGNMENT
+ bool "Enable checking of pointers alignment"
+ depends on KERNEL_UBSAN
+ help
+ This option enables detection of unaligned memory accesses.
+ Enabling this option on architectures that support unaligned
+ accesses may produce a lot of false positives.
+
+config KERNEL_UBSAN_NULL
+ bool "Enable checking of null pointers"
+ depends on KERNEL_UBSAN
+ help
+ This option enables detection of memory accesses via a
+ null pointer.
+
+config KERNEL_KASAN
+ bool "Compile the kernel with KASan: runtime memory debugger"
+ select KERNEL_SLUB_DEBUG
+ depends on (x86_64 || aarch64)
+ help
+ Enables kernel address sanitizer - runtime memory debugger,
+ designed to find out-of-bounds accesses and use-after-free bugs.
+ This is strictly a debugging feature and it requires a gcc version
+ of 4.9.2 or later. Detection of out of bounds accesses to stack or
+ global variables requires gcc 5.0 or later.
+ This feature consumes about 1/8 of available memory and brings about
+ ~x3 performance slowdown.
+ For better error detection enable CONFIG_STACKTRACE.
+ Currently CONFIG_KASAN doesn't work with CONFIG_DEBUG_SLAB
+ (the resulting kernel does not boot).
+
+config KERNEL_KASAN_EXTRA
+ bool "KAsan: extra checks"
+ depends on KERNEL_KASAN && KERNEL_DEBUG_KERNEL
+ help
+ This enables further checks in the kernel address sanitizer, for now
+ it only includes the address-use-after-scope check that can lead
+ to excessive kernel stack usage, frame size warnings and longer
+ compile time.
+ https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81715 has more
+
+
+choice
+ prompt "Instrumentation type"
+ depends on KERNEL_KASAN
+ default KERNEL_KASAN_OUTLINE
+
+config KERNEL_KASAN_OUTLINE
+ bool "Outline instrumentation"
+ help
+ Before every memory access compiler insert function call
+ __asan_load*/__asan_store*. These functions performs check
+ of shadow memory. This is slower than inline instrumentation,
+ however it doesn't bloat size of kernel's .text section so
+ much as inline does.
+
+config KERNEL_KASAN_INLINE
+ bool "Inline instrumentation"
+ help
+ Compiler directly inserts code checking shadow memory before
+ memory accesses. This is faster than outline (in some workloads
+ it gives about x2 boost over outline instrumentation), but
+ make kernel's .text size much bigger.
+ This requires a gcc version of 5.0 or later.
+
+endchoice
+
+config KERNEL_KCOV
+ bool "Compile the kernel with code coverage for fuzzing"
+ select KERNEL_DEBUG_FS
+ help
+ KCOV exposes kernel code coverage information in a form suitable
+ for coverage-guided fuzzing (randomized testing).
+
+ If RANDOMIZE_BASE is enabled, PC values will not be stable across
+ different machines and across reboots. If you need stable PC values,
+ disable RANDOMIZE_BASE.
+
+ For more details, see Documentation/kcov.txt.
+
+config KERNEL_KCOV_ENABLE_COMPARISONS
+ bool "Enable comparison operands collection by KCOV"
+ depends on KERNEL_KCOV
+ help
+ KCOV also exposes operands of every comparison in the instrumented
+ code along with operand sizes and PCs of the comparison instructions.
+ These operands can be used by fuzzing engines to improve the quality
+ of fuzzing coverage.
+
+config KERNEL_KCOV_INSTRUMENT_ALL
+ bool "Instrument all code by default"
+ depends on KERNEL_KCOV
+ default y if KERNEL_KCOV
+ help
+ If you are doing generic system call fuzzing (like e.g. syzkaller),
+ then you will want to instrument the whole kernel and you should
+ say y here. If you are doing more targeted fuzzing (like e.g.
+ filesystem fuzzing with AFL) then you will want to enable coverage
+ for more specific subsets of files, and should say n here.
+
config KERNEL_TASKSTATS
bool "Compile the kernel with task resource/io statistics and accounting"
default n
bool "Compile the kernel with SCSI generic v4 support for any block device"
default n
+config KERNEL_TRANSPARENT_HUGEPAGE
+ bool
+
+choice
+ prompt "Transparent Hugepage Support sysfs defaults"
+ depends on KERNEL_TRANSPARENT_HUGEPAGE
+ default KERNEL_TRANSPARENT_HUGEPAGE_ALWAYS
+
+ config KERNEL_TRANSPARENT_HUGEPAGE_ALWAYS
+ bool "always"
+
+ config KERNEL_TRANSPARENT_HUGEPAGE_MADVISE
+ bool "madvise"
+endchoice
+
+config KERNEL_HUGETLBFS
+ bool
+
+config KERNEL_HUGETLB_PAGE
+ bool "Compile the kernel with HugeTLB support"
+ select KERNEL_TRANSPARENT_HUGEPAGE
+ select KERNEL_HUGETLBFS
+ default n
+
config KERNEL_MAGIC_SYSRQ
bool "Compile the kernel with SysRq support"
default y
select KERNEL_DEBUG_KERNEL
default n
+config KERNEL_LOCKUP_DETECTOR
+ bool "Compile the kernel with detect Hard and Soft Lockups"
+ depends on KERNEL_DEBUG_KERNEL
+ help
+ Say Y here to enable the kernel to act as a watchdog to detect
+ hard and soft lockups.
+
+ Softlockups are bugs that cause the kernel to loop in kernel
+ mode for more than 20 seconds, without giving other tasks a
+ chance to run. The current stack trace is displayed upon
+ detection and the system will stay locked up.
+
+ Hardlockups are bugs that cause the CPU to loop in kernel mode
+ for more than 10 seconds, without letting other interrupts have a
+ chance to run. The current stack trace is displayed upon detection
+ and the system will stay locked up.
+
+ The overhead should be minimal. A periodic hrtimer runs to
+ generate interrupts and kick the watchdog task every 4 seconds.
+ An NMI is generated every 10 seconds or so to check for hardlockups.
+
+ The frequency of hrtimer and NMI events and the soft and hard lockup
+ thresholds can be controlled through the sysctl watchdog_thresh.
+
+config KERNEL_DETECT_HUNG_TASK
+ bool "Compile the kernel with detect Hung Tasks"
+ depends on KERNEL_DEBUG_KERNEL
+ default KERNEL_LOCKUP_DETECTOR
+ help
+ Say Y here to enable the kernel to detect "hung tasks",
+ which are bugs that cause the task to be stuck in
+ uninterruptible "D" state indefinitely.
+
+ When a hung task is detected, the kernel will print the
+ current stack trace (which you should report), but the
+ task will stay in uninterruptible state. If lockdep is
+ enabled then all held locks will also be reported. This
+ feature has negligible overhead.
+
+config KERNEL_WQ_WATCHDOG
+ bool "Compile the kernel with detect Workqueue Stalls"
+ depends on KERNEL_DEBUG_KERNEL
+ help
+ Say Y here to enable stall detection on workqueues. If a
+ worker pool doesn't make forward progress on a pending work
+ item for over a given amount of time, 30s by default, a
+ warning message is printed along with dump of workqueue
+ state. This can be configured through kernel parameter
+ "workqueue.watchdog_thresh" and its sysfs counterpart.
+
+config KERNEL_DEBUG_ATOMIC_SLEEP
+ bool "Compile the kernel with sleep inside atomic section checking"
+ depends on KERNEL_DEBUG_KERNEL
+ help
+ If you say Y here, various routines which may sleep will become very
+ noisy if they are called inside atomic sections: when a spinlock is
+ held, inside an rcu read side critical section, inside preempt disabled
+ sections, inside an interrupt, etc...
+
+config KERNEL_DEBUG_VM
+ bool "Compile the kernel with debug VM"
+ depends on KERNEL_DEBUG_KERNEL
+ help
+ Enable this to turn on extended checks in the virtual-memory system
+ that may impact performance.
+
+ If unsure, say N.
+
config KERNEL_PRINTK_TIME
bool "Enable printk timestamps"
default y
config KERNEL_PROC_VMCORE
bool
+config KERNEL_PROC_KCORE
+ bool
+
config KERNEL_CRASH_DUMP
depends on i386 || x86_64 || arm || armeb
select KERNEL_KEXEC
select KERNEL_PROC_VMCORE
+ select KERNEL_PROC_KCORE
bool "Enable support for kexec crashdump"
default y
config KERNEL_FREEZER
bool
- default y if KERNEL_CGROUP_FREEZER
config KERNEL_CGROUP_FREEZER
- bool "Freezer cgroup subsystem"
- default y
+ bool "legacy Freezer cgroup subsystem"
+ default n
+ select KERNEL_FREEZER
help
Provides a way to freeze and unfreeze all tasks in a
cgroup.
+ (legacy cgroup1-only controller, in cgroup2 freezer
+ is integrated in the Memory controller)
config KERNEL_CGROUP_DEVICE
- bool "Device controller for cgroups"
- default y
+ bool "legacy Device controller for cgroups"
+ default n
help
Provides a cgroup implementing whitelists for devices which
a process in the cgroup can mknod or open.
+ (legacy cgroup1-only controller)
+
+ config KERNEL_CGROUP_HUGETLB
+ bool "HugeTLB controller"
+ default y if KERNEL_HUGETLB_PAGE
+ depends on KERNEL_HUGETLB_PAGE
config KERNEL_CGROUP_PIDS
bool "PIDs cgroup subsystem"
Provides enforcement of process number limits in the scope of a
cgroup.
+ config KERNEL_CGROUP_RDMA
+ bool "RDMA controller for cgroups"
+ default y
+
+ config KERNEL_CGROUP_BPF
+ bool "Support for eBPF programs attached to cgroups"
+ default y
+
config KERNEL_CPUSETS
bool "Cpuset support"
default y if !SMALL_FLASH
config KERNEL_MEMCG
bool "Memory Resource Controller for Control Groups"
default y if !SMALL_FLASH
+ select KERNEL_FREEZER
depends on KERNEL_RESOURCE_COUNTERS || !LINUX_3_18
help
Provides a memory resource controller that manages both anonymous
config KERNEL_MEMCG_SWAP
bool "Memory Resource Controller Swap Extension"
- default n
+ default y if !SMALL_FLASH
depends on KERNEL_MEMCG
help
Add swap management feature to memory resource controller. When you
config KERNEL_BLK_DEV_THROTTLING
bool "Enable throttling policy"
- default y if TARGET_brcm2708
+ default y if TARGET_bcm27xx
config KERNEL_BLK_DEV_THROTTLING_LOW
bool "Block throttling .low limit interface support (EXPERIMENTAL)"
files in a cgroup which can be useful for debugging.
config KERNEL_NET_CLS_CGROUP
- bool "Control Group Classifier"
- default y
+ bool "legacy Control Group Classifier"
+ default n
- config KERNEL_NETPRIO_CGROUP
- bool "Network priority cgroup"
- default y
+ config KERNEL_CGROUP_NET_CLASSID
+ bool "legacy Network classid cgroup"
+ default n
+
+ config KERNEL_CGROUP_NET_PRIO
+ bool "legacy Network priority cgroup"
+ default n
endif
endif
-#
-# LXC related symbols
-#
-
-config KERNEL_LXC_MISC
- bool "Enable miscellaneous LXC related options"
+config KERNEL_DEVPTS_MULTIPLE_INSTANCES
+ bool "Support multiple instances of devpts"
default y if !SMALL_FLASH
+ help
+ Enable support for multiple instances of devpts filesystem.
+ If you want to have isolated PTY namespaces (eg: in containers),
+ say Y here. Otherwise, say N. If enabled, each mount of devpts
+ filesystem with the '-o newinstance' option will create an
+ independent PTY namespace.
+
+config KERNEL_POSIX_MQUEUE
+ bool "POSIX Message Queues"
+ default y if !SMALL_FLASH
+ help
+ POSIX variant of message queues is a part of IPC. In POSIX message
+ queues every message has a priority which decides about succession
+ of receiving it by a process. If you want to compile and run
+ programs written e.g. for Solaris with use of its POSIX message
+ queues (functions mq_*) say Y here.
-if KERNEL_LXC_MISC
-
- config KERNEL_DEVPTS_MULTIPLE_INSTANCES
- bool "Support multiple instances of devpts"
- default y
- help
- Enable support for multiple instances of devpts filesystem.
- If you want to have isolated PTY namespaces (eg: in containers),
- say Y here. Otherwise, say N. If enabled, each mount of devpts
- filesystem with the '-o newinstance' option will create an
- independent PTY namespace.
-
- config KERNEL_POSIX_MQUEUE
- bool "POSIX Message Queues"
- default y
- help
- POSIX variant of message queues is a part of IPC. In POSIX message
- queues every message has a priority which decides about succession
- of receiving it by a process. If you want to compile and run
- programs written e.g. for Solaris with use of its POSIX message
- queues (functions mq_*) say Y here.
-
- POSIX message queues are visible as a filesystem called 'mqueue'
- and can be mounted somewhere if you want to do filesystem
- operations on message queues.
+ POSIX message queues are visible as a filesystem called 'mqueue'
+ and can be mounted somewhere if you want to do filesystem
+ operations on message queues.
-endif
config KERNEL_SECCOMP_FILTER
bool
select KERNEL_FS_POSIX_ACL
default y if USE_FS_ACL_ATTR
- config KERNEL_HFSPLUG_FS_POSIX_ACL
+ config KERNEL_HFSPLUS_FS_POSIX_ACL
bool "Enable POSIX ACL for HFS+ Filesystems"
select KERNEL_FS_POSIX_ACL
default y if USE_FS_ACL_ATTR